Are my NOS RFT ECC83s /Thin plates for my Marshall?

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by daneswede1, Dec 14, 2005.


  1. daneswede1

    daneswede1 Member

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    I bought some RFT ECC83s off a reputable guy in FLa to put into my Marshall 2203. Anyway, Took them to my tech to install and my tech (he sells tubes :>)) I know what your thinking, said that these particualr RFTs have thinner plates and hence will make my Marshall sound a little thinner than say an RFT 12ax7? Whats the differance? I dont really understand this? Cant I just put these in my amp. Im having some TUng sol 12ax7s put in the amp for now but when I get the amp home I was gonna switch out the TUng sols and try the RFT ECC83s anyway just to hear the differance. Been researching the RFTs and a lot of people like them. Did I buy the weaker ones as in the ECC83s and not the 12ax7s? THx for any info here. Very confused.
     
  2. Roodboy

    Roodboy Supporting Member

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    I think ECC83 is the European designation for a 12ax7.
    As far as the plates being thinner, is that thinner than the plates on the tubes that were in there or other RFT's?
    I know there are RFT's with two different labels, one has something like a small "n" and the other kind of looks like a rams head.
    I've played both in a 82 Marshall 2204 didn't hear any difference betwen the two and thought they both sounded great.
    A little more high end than a Mullard I 63 ECC83 but not as much mid. A really aggressive rockin' tube.
    Try'em you'll probably like'em.
     
  3. Timbre Wolf

    Timbre Wolf GoldMember Supporter Gold Supporting Member

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    Do you know what I'm thinking? I'm thinking that your tech doesn't know what he's talking about! Or maybe he does - did he offer to relieve you of these inferior RFTs?

    ECC83 is synonymous with 12AX7. Some RFTs are labeled differently (or not at all), but most often, they've got the "n" symbol (for Röhrenwerk Neuhaus). Try one in your amp, and go from there. If that Tung Sol is an original (not one of the new Russian ones), my guess is that you'll keep it as the main input valve, and that you might like the RFT as the next gain valve - that would better preserve your cleans, since the RFT breaks up earlier than most 12AX7s (or ECC83s).

    - T
     
  4. daneswede1

    daneswede1 Member

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    No, He didnt want my RFTS. I think the Tung Sols are Original but Ill have to double check that. I fired up the 2203x Marshall today and the Mullard EL34 reissues and Tung Sols sound really good. He tightened up some of the parts in the Marshall as well that they missed before initially shipping the amp to Sam Ash which is where i bought it. He also found a wrong value/ screen resistor in the amp Marshall put in there which is why I had the HT FUse blowing out on me. ANyway, Im gonna put the RFTs in my 1981 2203 I bet they will sound good in that one . THere are Svetlana C Wing EL34s in the 81 along with Mesa Chinese 12ax7s. Im gonna dump the Chinese Mesas and thats where the RFTs will go! i bet it will rock. More later to come. I gotta figure out how to post some clips
     
  5. Blue Strat

    Blue Strat Member

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    The RFTs should be fine in your Marshall or ANY amp that calls for 12AX7/ECC83s.
     
  6. tybone

    tybone Member

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    I love vintage tung sol's. A nice combination of sparkle and grind. The RFT's I find a bit more midrange focussed and meaty with a bit less sparkle.
     
  7. daneswede1

    daneswede1 Member

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    \


    I installed these as follows in my 1981 Marshall 2203.
    V1- Chinese 12ax7a
    V2- NOS RFT "n" logo ECC83
    V3- 9th gen. Chinese.
    Sounded good this way. THe early nbreakup of the RFT wasnt as pronounced with her being in the V2 slot MR RFT. I went back to the Chinese 12ax7a in the V1 and the 2-9th gen chinese 12ax7 in the V2-V3. I like that setup. SImple yet effective tone for me. I want to try some BRIMARS NOS CV4004s. Maybe one in the V1 instead of the 12ax7a Chin.
     
  8. daneswede1

    daneswede1 Member

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    THanks for the tip. I figured these tubes would be fine. Just a tad Midrangey IMO and yes they do break up early as well. Good tubes though.

    I ended up using the 9th gen chinese in the V2-V3 and a Shuguang CHinese in the V1. Maybe not the best tubes but sounded really good in my 81 2203. HOpe they last.
    Im still noodling with the reissue 2203x as far as the preamp tubes. THe 81 has C WING Svetlana EL34s. Very warm and songey mids. Nice tubes. I have a QUAD set of NOS SIEMENS EL34s I want to put in the 81 2203 when the Svets run out of gas!:>)
     

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